cmd/compile: add -msan option
The -msan option causes the compiler to add instrumentation for the
C/C++ memory sanitizer. Every memory read/write will be preceded by
a call to msanread/msanwrite.
This CL passes tests but is not usable by itself. The actual
implementation of msanread/msanwrite in the runtime package, and support
for -msan in the go tool and the linker, and tests, will follow in
subsequent CLs.
Change-Id: I3d517fb3e6e65d9bf9433db070a420fd11f57816
Reviewed-on: https://go-review.googlesource.com/16160
Reviewed-by: David Crawshaw <crawshaw@golang.org>
diff --git a/src/cmd/compile/doc.go b/src/cmd/compile/doc.go
index 59c660b..f70c1cf 100644
--- a/src/cmd/compile/doc.go
+++ b/src/cmd/compile/doc.go
@@ -66,6 +66,8 @@
Write memory profile for the compilation to file.
-memprofilerate rate
Set runtime.MemProfileRate for the compilation to rate.
+ -msan
+ Insert calls to C/C++ memory sanitizer.
-nolocalimports
Disallow local (relative) imports.
-o file
diff --git a/src/cmd/compile/internal/gc/builtin.go b/src/cmd/compile/internal/gc/builtin.go
index f09dd56..5b2ddbd 100644
--- a/src/cmd/compile/internal/gc/builtin.go
+++ b/src/cmd/compile/internal/gc/builtin.go
@@ -155,6 +155,8 @@
"func @\"\".racewrite (? uintptr)\n" +
"func @\"\".racereadrange (@\"\".addr·1 uintptr, @\"\".size·2 uintptr)\n" +
"func @\"\".racewriterange (@\"\".addr·1 uintptr, @\"\".size·2 uintptr)\n" +
+ "func @\"\".msanread (@\"\".addr·1 uintptr, @\"\".size·2 uintptr)\n" +
+ "func @\"\".msanwrite (@\"\".addr·1 uintptr, @\"\".size·2 uintptr)\n" +
"\n" +
"$$\n"
diff --git a/src/cmd/compile/internal/gc/builtin/runtime.go b/src/cmd/compile/internal/gc/builtin/runtime.go
index 6210f10..9301757 100644
--- a/src/cmd/compile/internal/gc/builtin/runtime.go
+++ b/src/cmd/compile/internal/gc/builtin/runtime.go
@@ -193,3 +193,7 @@
func racewrite(uintptr)
func racereadrange(addr, size uintptr)
func racewriterange(addr, size uintptr)
+
+// memory sanitizer
+func msanread(addr, size uintptr)
+func msanwrite(addr, size uintptr)
diff --git a/src/cmd/compile/internal/gc/go.go b/src/cmd/compile/internal/gc/go.go
index 79b9d9f..c1899ef 100644
--- a/src/cmd/compile/internal/gc/go.go
+++ b/src/cmd/compile/internal/gc/go.go
@@ -511,6 +511,8 @@
var racepkg *Pkg // package runtime/race
+var msanpkg *Pkg // package runtime/msan
+
var typepkg *Pkg // fake package for runtime type info (headers)
var typelinkpkg *Pkg // fake package for runtime type info (data)
@@ -645,6 +647,8 @@
var flag_race int
+var flag_msan int
+
var flag_largemodel int
// Whether we are adding any sort of code instrumentation, such as
diff --git a/src/cmd/compile/internal/gc/lex.go b/src/cmd/compile/internal/gc/lex.go
index b9ce4cb..0093e1b 100644
--- a/src/cmd/compile/internal/gc/lex.go
+++ b/src/cmd/compile/internal/gc/lex.go
@@ -200,6 +200,7 @@
obj.Flagcount("l", "disable inlining", &Debug['l'])
obj.Flagcount("live", "debug liveness analysis", &debuglive)
obj.Flagcount("m", "print optimization decisions", &Debug['m'])
+ obj.Flagcount("msan", "build code compatible with C/C++ memory sanitizer", &flag_msan)
obj.Flagcount("nolocalimports", "reject local (relative) imports", &nolocalimports)
obj.Flagstr("o", "write output to `file`", &outfile)
obj.Flagstr("p", "set expected package import `path`", &myimportpath)
@@ -249,6 +250,14 @@
if flag_race != 0 {
racepkg = mkpkg("runtime/race")
racepkg.Name = "race"
+ }
+ if flag_msan != 0 {
+ msanpkg = mkpkg("runtime/msan")
+ msanpkg.Name = "msan"
+ }
+ if flag_race != 0 && flag_msan != 0 {
+ log.Fatal("can not use both -race and -msan")
+ } else if flag_race != 0 || flag_msan != 0 {
instrumenting = true
}
@@ -623,6 +632,9 @@
} else if flag_race != 0 {
suffixsep = "_"
suffix = "race"
+ } else if flag_msan != 0 {
+ suffixsep = "_"
+ suffix = "msan"
}
file = fmt.Sprintf("%s/pkg/%s_%s%s%s/%s.a", goroot, goos, goarch, suffixsep, suffix, name)
diff --git a/src/cmd/compile/internal/gc/racewalk.go b/src/cmd/compile/internal/gc/racewalk.go
index a2b09cd..7770f74 100644
--- a/src/cmd/compile/internal/gc/racewalk.go
+++ b/src/cmd/compile/internal/gc/racewalk.go
@@ -18,6 +18,11 @@
// 3. It inserts a call to raceread before each memory read.
// 4. It inserts a call to racewrite before each memory write.
//
+// For flag_msan:
+//
+// 1. It inserts a call to msanread before each memory read.
+// 2. It inserts a call to msanwrite before each memory write.
+//
// The rewriting is not yet complete. Certain nodes are not rewritten
// but should be.
@@ -26,11 +31,11 @@
// Do not instrument the following packages at all,
// at best instrumentation would cause infinite recursion.
-var omit_pkgs = []string{"runtime", "runtime/race"}
+var omit_pkgs = []string{"runtime", "runtime/race", "runtime/msan"}
// Only insert racefuncenter/racefuncexit into the following packages.
// Memory accesses in the packages are either uninteresting or will cause false positives.
-var noinst_pkgs = []string{"sync", "sync/atomic"}
+var norace_inst_pkgs = []string{"sync", "sync/atomic"}
func ispkgin(pkgs []string) bool {
if myimportpath != "" {
@@ -49,25 +54,27 @@
return
}
- if !ispkgin(noinst_pkgs) {
+ if flag_race == 0 || !ispkgin(norace_inst_pkgs) {
instrumentlist(fn.Nbody, nil)
// nothing interesting for race detector in fn->enter
instrumentlist(fn.Func.Exit, nil)
}
- // nodpc is the PC of the caller as extracted by
- // getcallerpc. We use -widthptr(FP) for x86.
- // BUG: this will not work on arm.
- nodpc := Nod(OXXX, nil, nil)
+ if flag_race != 0 {
+ // nodpc is the PC of the caller as extracted by
+ // getcallerpc. We use -widthptr(FP) for x86.
+ // BUG: this will not work on arm.
+ nodpc := Nod(OXXX, nil, nil)
- *nodpc = *nodfp
- nodpc.Type = Types[TUINTPTR]
- nodpc.Xoffset = int64(-Widthptr)
- nd := mkcall("racefuncenter", nil, nil, nodpc)
- fn.Func.Enter = concat(list1(nd), fn.Func.Enter)
- nd = mkcall("racefuncexit", nil, nil)
- fn.Func.Exit = list(fn.Func.Exit, nd)
+ *nodpc = *nodfp
+ nodpc.Type = Types[TUINTPTR]
+ nodpc.Xoffset = int64(-Widthptr)
+ nd := mkcall("racefuncenter", nil, nil, nodpc)
+ fn.Func.Enter = concat(list1(nd), fn.Func.Enter)
+ nd = mkcall("racefuncexit", nil, nil)
+ fn.Func.Exit = list(fn.Func.Exit, nd)
+ }
if Debug['W'] != 0 {
s := fmt.Sprintf("after instrument %v", fn.Func.Nname.Sym)
@@ -427,7 +434,8 @@
func isartificial(n *Node) bool {
// compiler-emitted artificial things that we do not want to instrument,
- // cant' possibly participate in a data race.
+ // can't possibly participate in a data race.
+ // can't be seen by C/C++ and therefore irrelevant for msan.
if n.Op == ONAME && n.Sym != nil && n.Sym.Name != "" {
if n.Sym.Name == "_" {
return true
@@ -489,13 +497,19 @@
n = treecopy(n, 0)
makeaddable(n)
var f *Node
- if t.Etype == TSTRUCT || Isfixedarray(t) {
+ if flag_msan != 0 {
+ name := "msanread"
+ if wr != 0 {
+ name = "msanwrite"
+ }
+ f = mkcall(name, nil, init, uintptraddr(n), Nodintconst(t.Width))
+ } else if flag_race != 0 && (t.Etype == TSTRUCT || Isfixedarray(t)) {
name := "racereadrange"
if wr != 0 {
name = "racewriterange"
}
f = mkcall(name, nil, init, uintptraddr(n), Nodintconst(t.Width))
- } else {
+ } else if flag_race != 0 {
name := "raceread"
if wr != 0 {
name = "racewrite"
diff --git a/src/cmd/compile/internal/gc/reflect.go b/src/cmd/compile/internal/gc/reflect.go
index e7138d9..d507949 100644
--- a/src/cmd/compile/internal/gc/reflect.go
+++ b/src/cmd/compile/internal/gc/reflect.go
@@ -1292,6 +1292,9 @@
if flag_race != 0 {
dimportpath(racepkg)
}
+ if flag_msan != 0 {
+ dimportpath(msanpkg)
+ }
dimportpath(mkpkg("main"))
}
}
diff --git a/src/cmd/compile/internal/gc/subr.go b/src/cmd/compile/internal/gc/subr.go
index c73c675..33b7dba 100644
--- a/src/cmd/compile/internal/gc/subr.go
+++ b/src/cmd/compile/internal/gc/subr.go
@@ -1643,7 +1643,7 @@
ul = UINF
goto out
- // hard with race detector
+ // hard with instrumented code
case OANDAND, OOROR:
if instrumenting {
ul = UINF
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index f0a1ddc..b1068dc 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -3037,7 +3037,7 @@
}
// General case, with no function calls left as arguments.
- // Leave for gen, except that race detector requires old form
+ // Leave for gen, except that instrumentation requires old form.
if !instrumenting {
return n
}
